As a runner, if you have had a lower limb injury you can almost guarantee your physiotherapist has gone on and on about your glutes. Foot injury…. strengthen your glutes, knee injury… strengthen your glutes, hip injury, you guessed it, look at your glutes. This is not because we only know exercises for one muscle group but more down to the importance of the gluteal muscles in walking and running.
The gluteal muscles are actually divided into three. The gluteus maximus (GMax), medius (GMed) and minimus (GMin) and each muscle has a different role to play. Our focus here is not on the bigger GMax, which extends the hip and propels us forwards but rather the smaller, deeper and often forgotten gluteus medius.
What does the gluteus medius do?
The specific position and fan shape of the muscle means that it has a dual role, with some fibers abducting the hip (taking the leg away from the body) and others medially rotating the femur. However when running it serves a very different role.
Being able to maintain a good position in a single-leg stance is required during both walking and running. The GMed acts to stabilize the femur (thigh) and pelvis during weight-bearing activities with the greatest GMed activation observed during the stance phase of gait, i.e. when the working leg is in contact with the ground as the other leg lifts off. When the muscle is unable to work efficiently due to pain, poor mechanics or weakness, the pelvis will drop on the opposite side to the weakness.
The gluteus medius also supports the pelvis during gait by producing rotation of the hip. It does so with the assistance of two other muscles, the gluteus minimus and tensor fascia latae (TFL), to prevent the collapse of the knee inward.
How to identify a weakness
An easy way to test if you have GMed weakness is to do a mini single leg squat. The signs of weakness include the pelvis dropping on the side of the leg off the ground, medial rotation or inward collapse of the knee of the leg on the ground and the body leaning excessively to one side. An example of inward collapse of the knee and excessive trunk lean is shown below.
A longer term consequence is over use of surrounding muscles like the TFL or gluteus maximus presenting as muscle tightness or even pain or injuries to compensate for weakness in the GMed.
Strengthening in the gluteus medius
It is important to strengthen this muscle due to the crucial role that it performs in running and preventing injuries to the lower limb. This requires loading the muscle with exercises performed on one leg. Unfortunately, the muscle is often not strong enough or being recruited in the right pattern or order to carry out these types of exercises straight away and therefore requires being trained in isolation or in non weight bearing using simpler, more specific movements. These include exercises such as (click for full demonstrations):